Answer:
Noise cancelling headphones have a microphone which listens to the ambient noise. The headphone then processes the sound and provides a wave to produce destructive interference. This cancels the ambient noise.
Explanation:
First, let us understand what interference is. Interference is the phenomenon that occurs when two waves superpose to form a wave which has a different wavelength, frequency, amplitude than the original two waves. When the crest of one wave superposes with the other waves crest then this results in the amplitude increasing. This is known as constructive interference. When the crest of one wave superposes with the other waves trough then this results in the amplitude decreasing. This known as destructive interference.
Noise cancelling headphones have a microphone which listens to the ambient noise. The headphone then processes the sound and provides a wave to produce destructive interference. This cancels the ambient noise.
Answer:
length of selfie-stick is 1.62 m
Explanation:
Given data
image size h1 = 5 mm = 5 ×
m
focal length = 4 mm = 4 × m
distance h2 = 2.032 m
to find out
How long of a selfie-stick
solution
here we find first magnification
that is M = h1 /h2
M = 5 × / 2.032
M = 2.46 ×
and we know M = p/q
so p = Mq = 2.46 × q
so we apply lens formula
1/f = 1/p - 1/q
1/ 4 × = 1 / 2.46 × q - 1/q
q = 1.622 m
so length of selfie-stick is 1.62 m
Landforms pushing up mountains and hills. water and wind can wear down land and create valleys and canyons
Something that is not magnetic
